Positive:
1. Smaug
Smaug’s intellect and personality combined with his large size and is nearly impossible to kill make him a great villain. While he might not be in all that many scenes, he’s a larger than life figure that informs the entire plot.
2. Balin
Balin is probably the most recognizable and most well-loved dwarf from the company. In the movies, he’s brought to life in a very endearing way that portrays his wisdom and loyalty.
His life story is also particularly interesting because he re-established Morea and his tomb was shown in The Fellowship of the Ring.
Negative:
1.Wargs
The terrifying wolves who, unsurprisingly, allied with the dark forces every time were certainly some of the most hostile creatures roaming Middle Earth.
However, although profoundly vicious, the wargs were not the most dangerous villains in this epic saga and therefore don't count as very high profile. Almost mechanically pledging allegiance to the Orcs and other malevolent forces, they were physically threatening but were never shown to be very intelligent creatures as such.